Many surgical procedures include the use of sutures, particularly for tissue fixation and repair, and often in endoscopic, arthroscopic or other minimally invasive procedures for effecting surgical procedures within a patient's body. Traditionally, once a suture is appropriately positioned with respect to the relevant tissue, the suture ends are knotted together to fix or otherwise repair the tissue. These suture knots may either be formed proximate to the fixation or repair site, or away from the surgical site and outside of the A surgical field. In the latter situation, so-called “knot pusher” devices and methods have been developed to transport the knotted region of the suture to the tissue or to another desired location. In either situation, knots may be difficult to make, difficult to properly tension and difficult to properly place, particularly in tight spaces.
Suture fixation techniques other than knotting have also been tried. For example, techniques and apparatus for performing frictional suture welding have been disclosed. Such frictional welding is generally accomplished by exposing the suture fixturing and/or directly exposing the suture material to ultrasonic energy. U.S. Pat. No. 3,515,848 to Winston et al. discloses devices and methods for ultrasonic suture welding. More recently, patents assigned to Axya Medical, Inc. of Beverly, Mass. (see, e.g., U.S. Pat. Nos. 5,417,700; 5,893,880; 6,174,324) have disclosed devices and methods involving the application of ultrasonic energy to weld sutures. This method, however, does not work with all popular suture materials, and proper welding can be sensitive to suture placement and configuration within the welding device.
Accordingly, there remains a need to fix sutures without the need to tie knots. In particular, it would be desirable to develop a system to weld lengths of popular suture materials, such as polydioxanone (PDS), to fix one length of suture to another without the need for knots. It would further be desirable to develop techniques for fixing sutures that use an energy source that is already commonplace in the surgical venue, thus eliminating the need for significant new capital investment.